The present invention relates to a compact zoom lens, particularly adapted for use with a 35 mm SLR camera, in which the focal length at the telephoto end extends into a so-called super telephoto region, the zoom ratio is more than four while at the same time the telephoto ratio (the ratio of the overall length to the maximum focal length) is extremely small.
In order to design a zoom lens in a compact size with a zoom ratio more than four and a maximum focal length which falls in the super telephoto range, it is very important to select the basic type of the zoom lens. For example, a so-called afocal type zoom lens in which a ray of light emerging from a third lens group (compensator) is made afocal is disclosed in Japanese Patent Publication 49/24295. As described in that publication, a second lens group (variator), the magnification of which is less than a unit magnification, is used. In specific examples thereof, the zoom ratio is about 3.3. If the zoom ratio were increased in that type of zoom lens, the total length would have to be increased or the refractive powers of the various lens groups would have to be made much stronger. Accordingly, it is difficult to compensate for various aberrations over the full range of focal length.